A DC-DC converter includes: a first converter including a pass transistor coupled between the first node and a first output, and a body diode connected in parallel to the pass transistor; a sensor coupled between both ends of the pass transistor and which detects a driving current; and a second converter which outputs a second power voltage lower than the first power voltage to a second output. The second converter includes a master inverting converter which outputs the second power voltage independently of the driving current, a slave inverting converter which outputs the second power voltage when the driving current is greater than a predetermined threshold or when the input power voltage is greater than a predetermined boosting voltage limit, and an inverting converter controller which controls operations of the master and slave inverting converters in first and second drive modes based on the driving current and the input power voltage.